title: Study to evaluate the impact of heat treatment on water soluble vitamins in milk.
abstract: OBJECTIVE
  To evaluate the effect of domestic boiling practice on the contents of water soluble vitamins of loose milk and quantitative comparison of these vitamins in Ultra High Temperature (UHT) treated packaged milk with that of boiled loose milk.
  
  
  METHODS
  Loose milk samples were collected from various localities of Karachi city (Pakistan). These samples were boiled in simulated household conditions for 5, 10 and 15 minutes. Ultra High Temperature (UHT) treated packaged milk samples of various brands were obtained from the local market. The aliquots were analyzed for water-soluble vitamins using High Performance Liquid Chromatography (HPLC) technique. The mean values and standard deviations for data were computed and compared as well as level of variations were also determined.
  
  
  RESULTS
  Conventional boiling caused destruction of water soluble vitamins in milk i.e. vitamin 81 content in fresh milk decreased from 0.037 mg/100 g to 0.027 mg/100 g after 15 min boiling, whereas vitamin B2 from 0.115 to 0.084 mg/100 g, vitamin B3 0.062 to 0.044 mg/100 g, vitamin B6 0.025 to 0.019 mg/100 g and folic acid 3.38 to 2.40 microg/100 g. This accounted for a post-boiling decrease of about 27, 27, 29, 24 and 36% in vitamins B1, B2, B3, B6 and folic acid respectively. The values for vitamins B1, B2, B3, B6 and folic acid determined in boiled milk were significantly lower than UHT treated packaged milk samples by 25.9, 75.0, 54.5, 63.16 and 38.1% respectively.
  
  
  CONCLUSIONS
  Conventional boiling caused drastic reduction in vitamin levels of loose milk samples. In comparison to this, UHT milk retained high levels of water soluble B-vitamins. Thus it could be envisaged that UHT treated milk provides better water soluble vitamins' nourishment than conventionally boiled milk (JPMA 60:909; 2010).
authors.affiliation: Food and Marine Resources Research Centre, Pakistan Council for Scientific and Industrial Research, Laboratories Complex, Karachi.
authors.lastname: Asadullah
authors.lastname: Khair-un-nisa
authors.forename: Omer Mukhtar
authors.initials: OM
authors.lastname: Tarar
authors.forename: Syed Abdul
authors.initials: SA
authors.lastname: Ali
authors.forename: Khalid
authors.initials: K
authors.lastname: Jamil
authors.forename: Askari
authors.initials: A
authors.lastname: Begum
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D005492:Folic Acid / Q000032:analysis; D005519:Food Preservation; D006358:Hot Temperature; D006801:Humans; D008892:Milk / Q000737:chemistry* / Q000382:microbiology; D009536:Niacinamide / Q000032:analysis; D010154:Pakistan; D012256:Riboflavin / Q000032:analysis; D012995:Solubility; D013242:Sterilization; D013831:Thiamine / Q000032:analysis; D013997:Time Factors; D025101:Vitamin B 6 / Q000032:analysis; D014803:Vitamin B Complex / Q000032:analysis; D014815:Vitamins / Q000032:analysis*; D014867:Water
chemical_list: D014815:Vitamins; D014867:Water; D014803:Vitamin B Complex; D009536:Niacinamide; D025101:Vitamin B 6; D005492:Folic Acid; D012256:Riboflavin; D013831:Thiamine